I bought a 20# a few weeks ago at the place where I get my welding gas, he also has medical gas and beverage gas. The tank was $70 plus $13.50 for the CO2. Then a week later I went a flea market and found a 20# alum. pepsi tank full of gas with a corn. regulator, and 5 line manifold with lines and ball lock connectors for $45. I don't know if anyone else will fill a pepsi tank or not but it says right on the tank I can get $75 deposit. Pretty good score I thought.